Method of inhibiting plant growth



United States Patent Int. Cl. A01n 9/20, 17/00 U.S. Cl. 71-121 2 ClaimsABSTRACT OF THE DISCLOSURE Herbicidal, nematocidal and fungicidal methodusing 1,S-diphenylisoalkylamines.

This application is a division of application Ser. No. 425,938, filedJan. 15, 1965, now U.S. Pat. No. 3,471,612, Oct. 10, 1969.

This invention relates to compositions and methods for the control ofplant diseases caused by plant pathogens. In still another aspect, itrelates to multifunctional uses of the compounds for control ofnematodes and selective herbicidal activity.

. Although compounds are'knownwhich are broadly effective against asmany as two major classes of pests, typically nematodes, or fungi andbacteria. It is surprising to discover a substance that is alsoherbicidal against the monocotyledonous subclass of anglospermous plantsin preemergent stage screening and being substantially nonphytotoxic todicotyledons. Thus selectivity of action has important economicimplications.

It has been found that nematodes and soil fungi frequently act togetherto bring about the onset of plant diseases and subsequent breakdown ofplant tissues. Parasitic nematodes puncture the epidermal layers ofroots and thus provide points of entry for pathogenic fungi. Nematodesare nonsegmented worms [phylum Nemate Thorne (1961)], found interrestial and aquatic environments as parasites of plants and animals.The term nem atode? as used' herein is intended to include all phases ofthe life cycle of the nematode, such as eggs, larvae and adults. 1

Plant parasitic nematodes, or eelworms, range inlength from less thanone sixty-fourth of an inch and seldom exceed one-eighth of an inch.They are found in all environments in which plants will grow, andconsequently all plants are subject to attack by this pest. The annualdamage either directly or indirectly incurred through nematode activitymaybe as great as three billion dollars.

Parasitic nematodes can be broadly classified as cyst forming,end'oparasitic, ectoparasitic, and above ground feeders, all of whichare known to affect a number of plants.

In crop protection against these soil pathogens various agriculturalpractices have been employed. Crop rotations have been practiced whichinclude at least one crop which does not serve as host to the pathogens.The breeding of resistant crop strains has occasionally met with somesuccess, but more frequently has been a failure. In many cases infestedland must be permanently abandoned insofar as its use for growing thedisease-susceptible crop is concerned.

Where the value of the land is high, or where expensive 3,545,956Patented Dec. 8, 1970 crops are involved, chemical measures for cropprotection have been found to be more economically desirable. However,since these same chemicals may be generally toxic to the crop plants, itis the customary practice to introduce the chemical several weeks beforeplanting the crop, allowing time for the chemical to act on thepathogen, and subsequently dissipate. This waiting period is adisadvantage to the farmer since it introduces an undesirable delay orshortening of his growing season. However, where the fumigant isselectively herbicidal, the use of such phytotoxic fumigants may bestrongly indicated, e.g., to inhibit germination of monocotyledonousgrasses in favor of dicotyledonous crops like beans.

It is an object of this invention to provide a new fumigant composition.A further object is the provision of a new method and multifunctionalcomposition for treating soil to obtain improved control over soildwelling plant pathogens, such as nematodes, and also herbicidalactivity on undesired plant species.

It has now been found that certain diphenylalkylamines exhibit theproperties of a selective plant protectant against nematodes and arepreferentially herbicidal toward monocotyledon plant seeds.

More specifically, this invention relates to chemical compounds of thegeneral formula:

wherein R, R, R" and R' represent hydrogen, lower alkyl or n is aninteger from one to three.

Preferred compounds are those where both ns are one,

and the Rs are positioned ortho and para.

Advantageous and preferred are those Where at least two of the Rs arehydrogen and both ns are one.

The methods of synthesis of the aforedescribed diphenylalkylamines aregenerally known and do not form a part of the invention of the presentdisclosure. Numerous references in the literature teach practical meansfor their synthesis, i.e., U.S. Pat. No. 1,921,424 to Nabenhauer. In anyevent, chemists skilled in the art of organic amine syntheses canreadily provide large scale methods of the active compounds of thisinvention.

' It will be understood that the salts of diphenyl lower alkyl aminesmay be readily prepared from the free compound by addition to thecompound of desired acid radicals which, in the case of the sulfate, forexample, may be accomplished by suspending the amine in warm water, andneutralizing with sulfuric acid. The solid amine sulfate willcrystallize out on concentration and cooling. The hydrochloride,acetate, and the like, may be similarly ,pre-' pared by neutralizingwith acetic acid, hydrochloric acid, or the like. V I

, Exemplary of the multifunctional compounds useful according to theteaching of this invention are the fole lowing:

1,3-dipheuylisopropylamine 1,3-diphenylisobutylamine1,3-diphenylisoamylamine 1,3-diphenylisohexylamine 31.S-diphenylisoheptylamine 1,3-di(o-nitrophenyl)isopropylamine1,3-di(2,4-dichlorophenyl) isopropylamine 1,3-di(o-methylphenyl)isopropylamine 1,3 -di p-methoxyphenyl isopropylamine Selectively as tothe possible optical isomers, or to the degree of ring substitution isnot deemed critical to insure the level of pesticidal activitydemonstrated by a reaction mixture comprising a major part ofdiphenylalkylamines.

Multifunctional compositions embodying the invention can be prepared inthe form of solids or liquids. Solid compositions, preferably in theform of wettable powders, are compounded to give homogeneousfree-flowing powder by mixing the active ingredient with finely-dividedsolids, clays, diatomaceous earth, synthetic fine silica or floursderived from walnut shell, redwood, soybean, cotton seed flour, or othersolid conditioning agents or carriers of the kind conventionallyemployed in preparing pest control compositions in solid form.

Even more preferable among solid compositions, in some instances, aregranules or pellets when the application is primarily to the soil.Granules may be prepared by impregnating granular diluents such asgranular Attaclay, or may be made by first extending powdered solid withpowdered diluent and subsequently granulating. Pellets are made byextruding moistened, powdered mixtures under high pressure through dies.

Pesticidal spray compositions of the invention can be prepared by mixingthe active ingredient with a suitable liquid diluent medium using a highor low boiling solvent, such as acetone. aromatics, and DMSO. Theresulting composition is then in the form of either a solution orsuspension of the active ingredient.

The nematocidal compositions of the invention, whether in the form ofsolids or liquids, for most applications may also include asurface-active agent of the kind sometimes referred to in the art as awetting, dispersing or emulsifying agent. These agents, which will bereferred to hereinafter more simply as surface-active agents, cause thecompositions to be easily dispersed in water to give aqueous sprays,whereby they can be applied as dispersing liquid sprays or gas-propelledsprays.

The surface-active agents employed can be of the anionic, cationic ornonionic type and include, for example, sodium and potassium oleate, theamine salts of oleic acids such as morpholine and dimethylamine oleates,the sulfonated animal and vegetable oils such as sulfonated fish, andcastor oils, sulfonated petroleum oils, sulfonated acyclic hydrocarbons,sodium salt of lignin sulfonic acid (goulac), alkyl naphthalene sodiumsulfonate and other wetting, dispersing and emulsifying agents such asthose listed in articles by McCutcheon in Soap and Chemical Specialties,vol. 31, Nos. 7-10 (1955). Including for example, the material known asTriton X-155 (100% alkylaryl polyether alcohol-US. Pat. No. 2,504.064).

Generally, the surface-active agent will not comprise more than about 1%to 10% by weight of the composition depending, of course, upon theparticular surfaceactive agent, the system in which it is placed, andthe result desired; in certain compositions, the percentage will be 1%or less. Usually, the minimum lower concentration will be 0.1%

The active compound is, of course, applied in an amount suflicient toexert the desired nematocidal or herbicidal action. The amount of theactive ingredient present in the compositions as actually applied forkilling nematodes and controlling fungi will vary with the manner ofapplication, the particular nematodes or fungi for which control issought, the purposes for which the application is being made, and likevariables. In general, however, the biologically active formulation willcontain from p.p.m. to 50,000 p.p.m. of the active ingredient.Concentrations as low as 1 p.p.m. can be effectively employed. For somerequirements stronger concentrations may be desirable up to a maximum of500,000 p.p.m. In field application, rates of /2 pound tothree-hundred-fifty pounds per acre of active ingredient (on an overallcoverage basis) are suitable, with rates in the 20 to pound range as anematocide being preferred, and 0.5 to 20 pounds as a fungicide pergallons of aqueous diluent also preferred. The optimum rate will dependon soil type, pathogen. and host species, and degree of controlrequired. If seed treatment, row treatment, or spot treatment is used,the actual per-acre rates will be lowered, since the entire area is notpermeated by the chemical but only the vicinity of the seedlings.

Various modifications and alterations of this invention will becomeapparent to those skilled in the art Without departing from the scopeand spirit of the invention and it should be understood that the latteris not necessarily limited to the aforementioned disclosure.

NEMATOCIDE TEST PROCEDURES Example 1 A dilution series is made with a2.5% stock solution of the test chemical. 1,3-diphenylisopropylamine(SK&F 24) as follows:

(1) 0.5 ml. of stock+9.5 ml. of distilled water10 ml. of 0.125%.

(2) 1 ml. of 1+9.0 ml. of distilled water-10 ml. of 0.0125%.

(3) 1 ml. of 2+9.0 ml. of distilled water-10 ml. of 0.00125 (4) 1 ml. of3+9.0 ml. of distilled water-10 ml. of 0.000125%.

0.2 ml. of nematode suspension (containing 500-750 nematodes per ml.) isadded to each of these dilutions to bring the final concentrations to0.1, 0.01, 0.001 and 0.0001 percent respectively.

The initial test organism used was a species of Panagrellus, a freeliving nematode, nourished on oatmeal soaked in water.

The laboratory standard nematocide used was hexyl resorcinol, whichgives a 100% kill at 0.01 percent.

A control (a pure nematode culture), and an untreated solvent check(solvent only added to nematode culture), were included in each testrun.

Initial screening was conducted at 0.1 and 0.01% concentration. If sometoxicity close to that of standard hexyl resorcinol was observed atthese concentrations, the testing was repeated at 0.1, 0.01, also at0.001 and 0.0001% concentrations. However, if toxicity were low, thetesting would be again repeated at 0.1 and 0.01%. Results of the tworuns are reported in Table I below.

TABLE I [Efleetiveness of 1,3-Diplienylisopropylamine, SKdzF 24, forControl of the Nematode Panagrellus] HERBICIDAL TEST PROCEDURE I Example2 l,3-diphenylisopropylamine, SK&F No. 24, was evaluated for selectiveherbicidal activity in a preemergent seed germination test proceduredescribed below.

One gram of test chemical is dissolved in 200 ml. of acetone. To this 80ml. of distilled wateris added. At thisconcentration of acetone noundesirable effects were noticed on either germination or growth. Thisgives a solution containing 1 gm. of test chemical/95 .8 gms. of acetoneplus water (w./w.), or 10,436 p.p.m. ($10,450 p;p.m.), or 1 gm. of testchemical/100 ml. of solvent (w./v.), ora 1% stock. solution. The stocksolution is furtherdiluted with distilled water to give the followingconcentrations of test chemicals:

0.5% or 5,225 p.p.m. 0.25% or 2,612.5 pfpImf 0.125% or 1,306.25 p.p.m.

Adso'rbeiitpape'f is cut 'to' fit the" bottom" of the pan" dishes andmoistened with ml. of distilled water. Ten seeds are placedin. .eachdishand 2 ml. of each test chemical are pipetted over the seeds. Petridishes containing the water control and the standards are similarlyprepared; After rolling each petri dish for distribution of testchemical, the petri dishes are covered and placed inthe Mangelsdorfgerminator set at 78 F. v

1 Results of two and three replicates of SK&F 24 and comparisons-to fourstandard herbicides, plus a control are. Shown in tabularforminTableII.

herbicidal to monocotyledons, such as wheat, and only slightlyphytotoxic to dicotyledonous seed, such as those of beans.

HERB-ICIDAL TEST PROCEDURE II Example 3 ducted, for a total of fiveplants at each concentration.

Also, a typical annual monocotyledon, such as barley, is dipped in asolution of the candidate herbicide con taining 0.1% Triton X-lOO untilrun-01f. The plants used are seven days old. The plants are grown inDixie cups, five plants to a cup, for each chemical and at eachconcentration. A single replicated test is conducted for a total of tenplants for each chemical at each concentration.

TABLE IL-SEED GE RMINATION Number (if days "Wheat var. Contender Beansvar. Valentine (a dlcotyledon) of incubation (a monocotyledon) .prior tocount Percent growth response 95 '.l"ercent Growth r p percent 4-5 6-7germi- Germi- R ark Compound W./v. Wheat Beans nation JG MG S1 S: S;nation* .I G MG S symptoms gggp tr rgn l i '94. j 0 s0 0 on 93 2 7e HCHControl (2) 94 0 94 0 0 0 77 0 34 43 (Wheat).

2 4%Ti'iclilofophenoxyacetlc,acld- 30 7 0 0 3 63 63 0 0 Growth curled Q'71" 0 0 7 0 0 60 20 0 40 andtwisted. m-.- 0 s 0 0 0 0 45 10 0 35 0 0 00 0 0 45 13 0 32 2-4 D V 2-4Diehlorophenoxyacetleacid 1 I 6o 0 0 30 30 Op 65 28 0 37 l 48 0 0 23 0 45 18 0 27 Twisted and dead. 35 0 .0 17 18 00 0 0 0 {j .2 '0 3 0 0 0 0 0 0 All dead after germi. J 'p' b h; H. q2,2-dich1oroproplonlc acidsodlumj; 1.90 0 I 60 0 0 I 90v 0 90 0 salt. 750 10 0 0 65 .80 0 78 2 50 20 5 25 0 0 73 '7 57 9 x y 10., 0 15.10 0' 7327 3 43 TelvaixMonllrgn) 3,(4-chlorophenyl)'.-l,1 dimethyl- 53 5 48 0urea.- l 58 1 8 0 18 47 0 =55 s 41 0 SK&Fz24 0.125, 5 6.. 100 10 0.25 56 100 0.5 .5 f (if 100 1. 0 5 6 80, 60, 50 2repl. (V v 6 90 Average of 4replicates. I

J G=Just germinating appearance ofroot rudiment; MG=maximum growth long,shoot 4%? long; S wheat=rootlets 1-2 The data of Table IIclearlyindicates that'as to in Results of runs with SK&F No. 24 comparedto four hibiting seed germination, SK&F No. 24 is selectively standards,plus acontrol, are, shown in Table III.

3 rootlets, long; Srwheat=rootlets %1" long, shoot y-l long;S1Bbeans=root 2-1 long. I

TABLE IIL-POST EMERGENT SCREENS Test plant Tomato (Annual dicotyledon)Concentration 0.1% 1.0%

Days 1-2 -14 1-2 6 10-14 Rating 012340123401234012340123401234 ControlA(HCH) 10 10 10 10 2,4 D 2,4 dichlorophcnoxyacetlc acid 2,4,5 '1 2,4,5trichlorophenoxyacetic acid Dalapon 2,2 diehloropropionic acidsodiumsalt 10 9 1 10 Telvar (Monuron) 3,(4-chloropl1eny1) 1,1 dimethylur 10 1O Sirnazine 2,chloro-4,6-bis (ethylamme) 1,3,5 triazine- Testplant Barley (Annual monocotyledon) Concentration .1% 1

Days '2 5 10-14 1-2 5 10.14

Rating .-012340123401234012340123401234 Control A (HCH) 10 10 10 10 2,4D2,4 dichlorophenoxyacetlc acid- 2,4,5 '1 2,4,5 triehlorophenoxyacetlcacid 2 Dalapon 2,2 dichloropropionic acid sodium salt. 2 8 5 5 10 10Telvar (Monuron) v 3,(4-ch1orophenyl) 1,1 dimethylurea 2 4 3 1 2 7 1 1 32 4 3 1 I5 1 3 5 2 2 8 Simazlne 2, ch1oro-4,6-bis (ethylarnine)1,3,5triazine 2 5 3 2 4 4 2 8 2 3 6 2---- 6 2 4 3 4 Ratio: 0=Norma1 (noinjury); 1=S1ight injury; 2=Moderate injury; 3=Severe injury; 4=Dead.

Criteria, such as, abscission, chlorosis, contact, curvanisanintegerfrom one to three. ture, formative, galling, killing, necrosis, abnormalpig- 2. A method of inhibiting the growth of monocotylement, quilling,adventitious roots and stunting, are used donous seeds which comprisestreating the seeds in an in rating. amount and concentration sufficientto inhibit the growth The data of Table III surprisingly indicates thatin postwith a diphenylalkylamine of the formula: emergent screens, SK&FNo. 24 is now herbicidal to dicotyledons, such as tomato plants, andnonphytotoxic to R monocotyledons, such as barley plants, a uniqueversatil- 5 ;@(CH2)HCH (CHZ)B@ ity of action. 1

Various modifications and alterations of this invention will becomeapparent to those skilled in the art without wherein: departing from thescope and spirit of the invention, and R are selected from the t groupconsistm of it should be understood that the latter is not necessarllyhydrogen halo, nitm, lower alkyl and lower alkgxy;

limited to the aforementioned disclosure. and

I claim:

1. A method of regulating the growth of plants which n 18 an Integerfrom one to three" comprises treating the plants in an amount andconcenv References Cited tration suflicient to inhibit the growth with adiphenylalkylamine of the formula: UNITED ES PATENTS 3,227,758 1/ 1966Richter et al. 71-121X R R" 3,227,759 1/1966 Richter et al. 71-121X R;@cm ncrr cm n 7 OTHER REFERENCES R 0 Plant Regulators, National Academyof Sciences, CBCC wherein; Positive Data Series No. 2, 1955, pages a, b,c, l and 30.

R, R, R", R are selected from the group consisting of JAMES O. THOMAS,JR., Primary Examiner hygrogen, halo, nitro, lower alkyl and loweralkoxy; 7 v an 5

